absent-mindedness: may refer to 1) a low level of attention ("blanking" or “zoning out”); or 2) intense attention to a single object of focus (hyperfocus) that makes a person oblivious to events around him/her; or 3) unwarranted distraction of attention from the object of focus by irrelevant thoughts or environmental events.

absolute threshold: the minimum amount of energy required for a sensory experience to be produced

action slips: a form of absent-mindedness where a person performs an action that was not intended; caused by not paying attention to what is going on.

activity theory: proposes that individuals prefer to remain active and productive in later life, even resisting disengagement from society - contrasts with social disengagement theory.

actor/observer biases: these refer to the tendency for (a) ‘actors’ to explain their own behaviour in situational terms and (b) observers to explain the behaviour of others in dispositional (person) terms.

adaptation: a feature of an organism that has been shaped by natural selection so that it enhances the fitness of its possessor. Alternative meaning: One adapts the way of living to the medicine and will then be forced to change one's living habits if one has to stop taking the medicine. An example of this is if one lives a very stressful life and manages to continue with this due to sedatives.

addiction: now little used term that referred to physical dependence and was associated with its negative effects, such as on social functioning.

adoption studies: employed to demonstrate the influence of genetics (as opposed to environment) by comparing the correlations between adopted children and either their biological parents or adoptive parents on a measurable trait (e.g. intelligence).

Adorno (1903-1969): was a philosopher, sociologist and composer. Within social psychology, is largely remembered for defining the authoritarian personality (characterised by intolerance of ambiguity, prejudiced attitudes and conformity to authority, with an emphasis on the influence of childhood experiences and internalisation) and the subsequent development of the F-scale (a measurement of the authoritarian personality).

agency: the belief that human beings are free to make decisions and have control over their own lives.

agency theory: theory developed by Milgram to explain why people obey orders that go against the conscience. When people see themselves as mere agents of another person, they will obey that person's orders, feeling themselves free of individual responsibility.

aggression: an action or a series of actions where the aim is to cause harm to another person or object.

alpha/beta bias: alpha bias refers to theories and research which assume real and enduring differences between men and women. Beta biastheories and research have traditionally ignored or minimised differences between men and women.

altruism (animal): an animal is considered to be engaging in altruistic behaviour when by so doing it increases the survival chances of another animal whilst decreasing its own.

altruism (human): as with animal altruism, this involves some cost to the altruist and some benefit to the recipient. Unlike animal altruism, there is often evidence of 'kindly intent' on the part of the altruist.

anally retentive: commonly abbreviated to "anal", is used conversationally to describe a person with such attention to detail that the obsession becomes an annoyance to others, and can be carried out to the detriment of the anal-retentive person.

animism: the belief that inanimate objects are alive and as such have life-like qualities such as feelings and intentions. A child may get angry and smack his bicycle because it 'made him get hurt'. Animism is a characteristic found in children in Piaget's second stage of intellectual development, the pre-operational stage. Piaget believed that animism was a characteristic of the child's egocentricreasoning - if the child has feelings and intentions, then so must all other things.

anonymity: a state for an individual within a crowd where each person loses their sense of individuality.

anorexia nervosa: (literally, a nervous loss of appetite) a disorder characterised by the pursuit of extreme thinness and by an extreme loss of weight.

antagonistic: opposition in physiological action; especially : interaction of two or more substances such that the action of any one of them on living cells or tissues is lessened.

antecedent control: a behavioural measure in which the intervention occurs before the behaviour arises. Antecedent procedures include education, attitude change and inducing or preventing behaviours by controlling the triggers which cause them to occur.

anterior pituitary: The front portion of the pituitary, a small gland in the head called the master gland. Hormones secreted by the anterior pituitary influence growth, sexual development, skin pigmentation, thyroid function, and adrenocortical function.

attenuator model of attention: Treisman's proposal that, instead of selecting one channel and blocking the others, the filtering mechanism (a) selects one channel and passes it on for semantic analysis, and (b) allows the unattended channels through for processing but in weakened (attenuated) form.

attitude: a personal belief of an evaluative nature, such as good or bad, likeable or not likeable, which influences our reactions towards people or things.

attribution (of causality): the way in which we infer the causes of our own or another person's behaviour according to a set of cognitive rules and biases. As a result of these strategies we decide whether a person's behaviour is caused by their own stable characteristics, or whether it is a result of situational influences.

attributional biases: in attribution theory, common faults in attributing causes to behaviour such that mistakes are made and the causes of behaviour are misunderstood. An example is self-serving bias in which we attribute our own good and worthy behaviours to personality factors (I gave my mum a bunch of flowers because I am kind) and any bad or unworthy behaviours to situational factors (I shouted at mum because I've got a headache).

auditory fatigue: occurs on exposure to intense sounds which cause a persistent reduction in apparent loudness.

autonomic conditioning (also called 'learned operant control of autonomic responses'): the conditioning of changes in autonomic (involuntary) responses (such as heart rate or blood pressure) by means of operant reinforcement.

authoritarian personality: personality style strongly associated with prejudiced attitudes, where the person is intolerant of ambiguity or uncertainty, submissive to those in authority and dismissive or arrogant towards those perceived to be of lower social status.

autonomic nervous system: part of the nervous system that maintains the normal functioning of the body's inner environment The ANS has two subdivisions: (a) the sympathetic division whose activity mobilises energy resources and prepares the body for action, and (b) the parasympathetic divisionwhose activity tends to conserve the body's energy resources and restore inner calm.

availability: in memory, the principle that remembering is determined by whether the information exists in long-term memory or not; forgetting implies that the information is destroyed.

availability heuristic: a rule of thumb used to make decisions about frequencies of events based on how easily relevant examples can be remembered a cognitive short cut

aversion therapy: a behavioural treatment that aims to rid the individual of an undesirable habit (e.g. smoking) by pairing the habit with unpleasant (aversive) consequences.